The present invention relates to visual indicators and in particular to a mishandling detector for use upon packages that require careful treatment in shipping.
Highly sensitive and critical materials, often having large monetary values, are shipped in containers marked for careful treatment. However, during transit these containers are often stored on their sides or even upside down seriously damaging the enclosed materials. Furthermore, loading and unloading of such containers may take place either in a conscious or unconscious disregard of the markings in a manner which likewise damages the materials and renders them defective. The cost of these mishandled materials is usually absorbed by the requisitioner who while he is not at fault does not know with whom the fault lies. Thus, a mishandling detector that permanently indicates improper treatment of packages would provide the requisitioner of such packages with knowledge that he is receiving mishandled material that may be seriously damaged and permit the cost of such material to be absorbed by the carrier at fault.
Existing visual indicators for package tilt or inversion do not adequately satisfy the need for permanent detection of mishandling. Various types of tilt or inversions indicators have been conceived, such as those taught by U.S. Pat. Nos. 3,926,144, 2,674,221, 3,207,122 and 3,688,734, each having a means for preserving its indication of improper package treatment. While these devices have preserved their indications to some extent, they have not proven entirely satisfactory in permanently indicating mishandling.